The present invention relates to an organopolysiloxanebased fiber treatment agent which is almost completely devoid of yellowing of the treated fiber.
Fiber treatment agents based on diorganopolysiloxane containing the --CH.sub.2 CH.sub.2 CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2 group have been used in order to impart lubricity to fibers and fibrous materials. for example, natural fiber such as cotton, flax, silk, wool, Angora, and mohair; regenerated fiber such as rayon and bemberg; semisynthetic fiber such as acetate; and synthetic fiber such as polyester, polyamide, polyacrylonitrile, polyvinyl chloride, vinylon, polyethylene, polypropylene, and spandex. Refer to Japanese Patent Publication Number 57-43673 (43,673/82). However, due to spontaneous oxidation, fiber treated with diorganopolysiloxane containing the--CH.sub.2 CH.sub.2 CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2 group yellows with the passage of time.